The monster black holes at the heart of galaxies may have originated
from galaxy collisions during the earliest period of universe, new
supercomputer models suggest.

Supermassive black holes ? millions to billions of times the mass
of our sun ? are thought to reside at the center of almost every galaxy. Astronomers
have found the presence of supermassive
black holes within the first billion years of the universe, meaning they
took much less time to form than current ideas suggest.

Now calculations on supercomputers suggest that mergers between
massive protogalaxies of the early universe provided a breeding ground for
supermassive black holes, each one forming over only 100 million years or so.
Scientists estimate the universe is 13.7 billion years old. [Black
Holes of the Universe]

Mergers between giant primordial galaxies are thought to have been
common in the early universe. Simulations run on supercomputers suggest that a merger
could have formed an unstable, rotating disk of gas, which funneled gas
amounting to more than a 100 million times the mass of the sun into a small cloud
in only 100,000 years. This cloud collapsed to give birth to a black hole,
which could then grow to a billion solar masses in about 100 million years by
sucking gas from the surrounding disk.

Previously,
astronomers had suggested supermassive black
holes, galaxies and other giant cosmic structures had formed gradually as
gravity drew small bits of matter together into larger and larger clumps.

"Our result shows that big structures, both galaxies and
massive black holes, build up quickly in the history of the universe,"
said study co-author Stelios Kazantzidis, an astronomer at Ohio State
University.

The
implications of this new discovery are far-reaching in our understanding of the
evolution
of the black holes and galaxies, Kazantzidis said.

"For example, the standard idea that a galaxy's properties
and the mass of its central black hole are related because the two grow in
parallel will have to be revised," Kazantzidis explained. "In our
model, the black hole grows much faster than the galaxy. So it could be that
the black hole is not regulated at all by the growth of the galaxy. It could be
that the galaxy is regulated by the growth of the black hole."

One important consequence of this model is that galaxies in the
very early universe should have much bigger central supermassive black holes
than expected, said the study's lead author, Lucio Mayer, an astrophysicist at
the University of Zurich in Switzerland. In comparison, galaxies nowadays
generally have central black holes appropriate for their size.

A number of instruments coming online in the next five to 10 years,
such as the James Webb Space Telescope and the Atacama Large Millimeter Array
(ALMA), are expected to be able to measure the masses of these early galaxies
and their central black holes to prove or disprove this model. ?"Possibly
new data from lots of other instruments might be able to provide an answer even
earlier," Mayer told SPACE.com.

According to Einstein?s theory of general relativity, ancient
galaxy mergers would have created massive gravitational waves ? ripples in the
very fabric of space and time whose remnants should still be detectable today.

New gravitational wave detectors, such as NASA's Laser
Interferometer Space Antenna, were designed to spot these waves directly,
opening a window into the workings of our cosmos. To interpret the results from
these detectors, however, scientists will need to know how supermassive black
holes formed. The new computer simulations should provide a clue, the
researchers noted.